Cyclosporin C is a natural and neutral, non-polar, cyclic group of oligopeptides with immunosuppressant and antifungal activity. Cyclosporin C is highly lipophilic and binds cyclophilin intracellular proteins, involved in protein folding.

• Immunosuppressant used to study cell-signaling in autoimmune diseases• Treatment of autoimmune disorders such as rheumatoid arthritis, systemic lupus erythematosus (SLE), and psoriasis• Antifungal• Used prevent rejection of grafts post-transplant due to cytotoxic effects of T-cells